Throughout this application, various publications are referenced by author and date within the text. Full citations for these publications may be found listed alphabetically at the end of the specification immediately preceding the claims. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.
The products of glycation and oxidation of proteins, Advanced Glycation Endproducts (AGEs), are an heterogeneous group of structures that accumulate in settings such as aging, diabetes, and renal failure (1-2). It has been reported that AGEs may form in euglycemic inflammatory environments, driven by the myeloperoxidase pathway (3). AGEs have been linked to alterations of cellular properties, including those eventuating in impaired cellular integrity and barrier properties; mediated, for example, by progressive glycoxidation and cross-linking of critical structural proteins. In addition, AGEs interact with specific cell surface binding sites to modulate cellular properties in a manner linked to activation of proinflammatory cell signalling pathways, especially those responsive to enhanced cellular oxidant stress. While a number of cell surface interaction sites for AGEs have been identified, the best-characterized cellular interaction site for AGEs is the Receptor for AGE (RAGE), a member of the immunoglobulin superfamily (4-9). Ligation of RAGE by AGEs perturbs cellular properties resulting in the generation of an environment conducive to the development of vascular lesions, as well as exaggerated proinflammatory host responses which may contribute to the complications that ensue in disorders such as diabetes (10-23).
The present invention provides a method for determining whether a compound is capable of inhibiting the interaction of a peptide with receptor for advanced glycation end product (RAGE), which comprises: (a) admixing: (i) the peptide, wherein amino groups of the peptide are inactivated by derivitization, (ii) RAGE or a fragment thereof, and (iii)the compound; (b) determining the amount of the peptide bound to RAGE or the fragment thereof, and (c) comparing the amount of bound peptide determined in step (b) with the amount determined when the peptide is admixed with RAGE or a fragment thereof in the absence of the compound, thereby determining whether the compound is capable of inhibiting the interaction of the peptide with RAGE or a fragment thereof, wherein a reduction in the amount of binding in the presence of the compound indicates that the compound is capable of inhibiting the interaction. The present invention also provides a method for inhibiting the interaction of an advanced glycation endproduct (AGE) with a receptor for advanced glycation endproduct (RAGE) in a subject which comprises administering to the subject a pharmaceutically acceptable amount of the compound identified in aforementioned screening method effective to inhibit the interaction between the AGE and the RAGE in the subject. The present invention also provides for a compound identified by the screening method and which is useful for the treatment of diabetes in a subject.